1. Field of the Invention
The present invention relates to an imaging element, an imaging device, and a method of deterring misappropriation of the imaging element. In particular, the invention relates to an imaging element disposed with plural photoelectric conversion elements for breaking down an image into plural pixels to generate image information representing the image and a shielding member that shields a partial region of a light-receiving region corresponding to the plural photoelectric conversion elements in order to determine an output level when the image is black, and to an imaging device using the imaging element.
2. Description of the Related Art
In recent years, the demand for digital cameras, such as digital still cameras and digital video cameras, has risen sharply in accompaniment with an increase in the resolution of imaging elements such as charge coupled devices (CCD) and complementary metal oxide semiconductors (CMOS) image sensor.
Among CCDs used in this type of digital camera, there are CCDs disposed with plural photoelectric conversion elements for breaking down an image (in this case, a subject image) into plural pixels to generate image information representing the image and a shielding member that shields a partial region of a light-receiving region corresponding to the plural photoelectric conversion elements in order to determine an output level when the image is black. The region shielded by the shielding member is usually called an optical black portion.
Digital cameras using this type of CCD set, on the basis of an output signal from the photoelectric conversion elements shielded by the shielding member, a level corresponding to black of an output signal from the photoelectric conversion elements not shielded by the shielding member, i.e., from the photoelectric conversion elements that output a signal representing an actual image. Thus, the phenomenon of smear, in which bright lines appear above and below a high-luminance portion in the image due to the scattering of incident light and the diffusion of photoelectrons generated within the CCD element, is corrected.
Assuming that a rental system, in which digital cameras housing a CCD disposed with an optical black portion are rented at a low fee to general users and recovered after use, will be constructed, there is a concern that the CCDs, which are relatively expensive, will be removed from the rented digital cameras by a third party and misappropriated.